Question

HashMap

public Map<String, BarrackData> barrack = new HashMap<String, BarrackData>();

BarrackData.java

public class BarrackData {
int A;
int B;
int C;
int D;
int E;
String Title;

public BarrackData(int a, int b, int c, int d, int e, String title) {
    A = a;
    B = b;
    C = c;
    D = d;
    P = p;
    Title = title;
}

How can I save this HashMap?
And load it?
I tried different methodes with Objectin/outputstream,
it ended up with NotSerializable, ObjectSteam and IO exception,
Where i have no clue how to deal with them.

Answer 1

Only Serializable classes may be serialized: Just add implements Serializable to your class:

public class BarrackData implements Serializable {

Note that to actually be serialized, all fields within the class must be Serializable, however java primitives, arrays (if the element type is Serializable), java.lang classes (like String) and Collections (if the element type is Serializable) are Serializable, so you’re OK.